PITA #1: In case you didn't know, 357 Sig brass comes with TWO different size primer holes, and the smaller of the two will not allow the decap pin on a Dillon carbide size die (BIG $$$!!!) to pass through unless you really lean on the handle and actually force the pin through and swage the hole up to a larger diameter. The regular size hole is .080", and the small size hole is about .060". Previously, I had identified Speer brass with the Lazy S on the headstamp as the chieft culprit, and use a .081" drill from a numbered drill set to drill out the cases before depriming.
I have discovered another headstamp with this problem, however, and that is 357 Sig R-P brass. Worse yet, I found a few R-P cases with the large primer hole, while most of them had the small primer hole. As such, be careful in going over your brass that you pick up before you try to resize it. So far, Federal and Wincester brass seem to have a standard size primer hole.
Now, as far as reloading and shooting 357 Sig ammo, there is a problem with the case bulging at the base, and this problem is NOT isolated to just Glocks! If you look at the image below, you can see that the back of the case is slightly sticking out of a stock Sig barrel, and with hot loads (1350 FPS - 1450 FPS with 125 grain bullet) the base will sqish out due to the thrust against the breech face.

The brass movement is shown below:

The solution for this is to get a Redding G-Rx push through die, and it can be used for 40 S&W brass, 357 Sig brass, and 10mm brass. This die should be used FIRST to reduce the base bulge, and then you can resize the case. If you do it the opposite way, the size die will leave a very clear ring of expanded brass at the base of the case (in cases that had hot loads...), and while the G-Rx die will iron it out, it will still leave a ring mark that you can see.
And last but not least, there is some very dangerous misinformation floating around out there, based on the fact that the 357 Sig case is BASED on a necked down 40 S&W case. This does NOT mean that you can use 40 S&W brass to make 357 Sig cases!! I have heard that there are actually some misguided people who have done this, which is why I am writing this post. If you run a 40 S&W case into a 357 Sig die, you will get a case that looks right, but is 20 mils too short! Now seeing as the 357 Sig headspaces on the CASE RIM and not the shoulder, when the round is fired the base of the case will stretch back 20 mils to the breech face, and a few reloads should be enough to have a full case head failure. To make this even worse, the SAAMI pressure for 40 S&W cases is 35,000 PSI, while the pressure for 357 Sig cases is 40,000 PSI, so you'll be running a 40 S&W case 5,000 PSI over its limit!! So if you run into a bottle necked case that has a 40 S&W headstamp, throw it away or crush it so some poor soul can't come along and use it later. If you run across somebody doing this kind of reloading, you might want to inform them of what they are doing, and NEVER go shooting with them!!
Be safe out there, people!!